Soulless
by EidolonLathi
Summary: When an unexpected mark turns up on his skin, Kakuzu needs little time to realize that this change predestines an annoying future. But wilfully ignoring this developments might be a way these events will not unfold to begin with? Kakuzu's intention seems to succeed, but Hidan falling into a sudden religious crisis brings this foretelling of old into focus again. A Loveless AU.


_Summary: When an unexpected mark turns up on his skin, Kakuzu needs little time to realize that this change predestines a future promising to be more annoying than anything else. But wilfully ignoring this developments might be a way these events will not unfold to begin with? Kakuzu's intention seems to succeed but Hidan falling into a sudden religious crisis brings this foretelling of old into focus again.  
__A Loveless AU._

_Author's Notes: Written for kakuhidaweek 2019. Day 01 – Prompt: Soulmates.  
__The soulmate-system of this fic got inspired by the manga Loveless. But you don't need to be familiar with it to understand the happenings of this story.  
__This fic is also cross posted to ao3. _

**Soulless**

When Kakuzu noticed the discoloured spot behind his ear, his first thought was that it somehow had to do with the modifications he had started to inflict upon his body. Making his body stronger by using not only the power of one but five hearts had been possible. Strengthening it even further by bringing this jutsu to the borders of what it was able to do had been possible as well. But all these adjustments came with a price, the stitches stabilizing his changed body only the most visible but by far not the most extreme.

So when the spot right behind his ear started to show a discolouring his first thought was that it had to be another side effect. Just as the sclera of his eyes had started to discolour shortly after he had decided to put his body under the influence of strengthening adjustments going even further than the initial jutsu. And now that spot… Kakuzu wasn't even sure for how long it had been there; his hair hid it away from sight when he was letting it down and whenever he was outside he was wearing his mask anyway.

It was when the discolouring started to form into a clearer shape that it became apparent it had to be more than his first assumptions. And it was when it had formed itself into a word when Kakuzu started to feel anxious about the entire matter and started his research, seeing if there was any information about the issue, about this unwelcome distraction that had decided to inflict itself upon him for no apparent reason.

It had needed only one single trip to the library to find out more about the matter.

Kakuzu's hands tightened on the book lying on the table in front of him and he needed all of his self-restriction to keep quiet and not letting hear the groan that wanted to escape his throat. No longer being able to stand what he was reading he lifted his gaze, his restless eyes coming to a halt at the few other people present at the library tables during this afternoon. A small group of three, teenagers, looking like they were busy with homework or the like.

Feeling he had regained some of his calm Kakuzu lowered his gaze again, continuing to read. He didn't even know the name of the town located in the Grass Nation he was presently in: He had passed it by while being on one of his bounty hunting trips and had spontaneously decided to try and do some research about his odd bruise when passing the local library by chance.

Continuing to read Kakuzu tried regaining his composure. The information in front of him might not have been what he had wanted to hear, but the entire matter sounded more annoying than a serious source of trouble. He quickly glanced to the right side, into the direction his ear was located, though there was of course no way he could see the discoloured spot without a mirror. At least the letters of the word were written in upper case letters, which improved Kakuzu's role in the entire mess significantly.

Deciding he's had enough of unpleasant surprises for this day he closed the book, bringing it back to the shelf where it belonged. The entire business was annoying, yes, but with a bit of luck he would never run into the other side of the equitation. He certainly wouldn't go and look where to find them. He would even go so far and not even try letting that odd silver line show up the book had been talking about; connection to the other side be damned.

Yes, being aware about the entire matter was a good thing after all but now the best would be to just ignore it, Kakuzu thought, leaving the library and continuing his way. His thoughts went to the bingo book stored away in his bag. There was a target he was currently trying to reach, that was definitely more important than words forming out of a sudden behind his ear and the entire ballast connected to it.

For the next twenty years Kakuzu did his best to forget about his true name.

And he might have succeeded forgetting it entirely if it hadn't been for Hidan.

Having decided to come to a halt for this day they had made rest at the inn of the small mountain town they had been passing through. Snow had announced itself this afternoon and now the night had fallen there had been little choice but to stay in the place, even though the location had turned out to be a bit too pricy of what Kakuzu found acceptable. This inn knew exactly travellers had little choice but to rest here with the next village being a good way further down the mountain, didn't they?

"Kakuzu? Don't tell me you're still mad about the price?"

Shaken out of his ponderings like this Kakuzu raised his gaze. Hidan of course had found no issue with it. Coming out of the bath he immediately had started wolfing down dinner. Beginning to look at loss he gestured at Kakuzu's own plate. "Your food is getting cold, you know?"

Suppressing a sigh Kakuzu started eating. "The prices they're charging here are still impossible."

Hidan shrugged his shoulders. "Might be, but what can we do? Looks like there's a snowstorm coming up this night. And this room is a nice one, isn't it?"

"What can we do indeed", Kakuzu said, no longer starting to bother hiding a sigh. At least the food tasted decent.

"We've been staying outside for almost a week now. If there's the time to stay inside for once again then it's now, right?"

Kakuzu halted, staring at his food. Was Hidan… was Hidan trying to cheer him up? The thought felt so unexpected and foreign, Kakuzu didn't know what to do with it. Beginning to feel restless he mumbled something that would pass as a sentiment of agreement and continued eating.

The gesture seemed to have been enough to chase away the cautious hesitation still having lingered on Hidan's face. Instead a bright smile appeared on his face. "And it was about time we got the chance to take a proper bath again."

To this Kakuzu only huffed, not bringing it over himself to admit he agreed with this point as well. After centuries during which he had been forced to dwell on the border of mere existing for more time than just once, he had fallen into the habit to not show more than indifference towards the most basic of needs.

But Hidan didn't seem to be bothered by this lukewarm response. Continuing to eat he started to fall into one of his rambling moods: "I for my part welcome our return into civilization; I was already starting to feel like a mountain monkey. This aside, certain prayer elements are just a bit difficult to get right in the open, you know?"

"Is this so?"

"Yeah. You know, I was starting to worry if there is something going wrong with the way I do my sacrifice rituals during our battles. But now I had the time to do a proper prayer in silence again I think that can't be it." Averting his gaze Hidan took a big bite of his food, utterly failing to act as if what he had just brought up was no longer causing him reason to worry.

Accepting the resignation that had lingered on the corners of his mind the entire evening Kakuzu took a long sip of his tea. The room was pricey but already payed for. And thought he didn't like to admit it, but it was the truth that the conditions they had been forced to stay outside for the better part of the last week had been somewhat dire. Kakuzu nodded towards Hidan's direction, a silent gesture signalling him to continue telling him about whatever Jashin related problem was keeping him busy.

Seeing this Hidan's eyes widened in surprise. Fidgeting around he looked at loss for words for a long moment until he finally continued: "Okay, look. It is like this: You know how my skin starts mirroring Jashin-sama's sense of decay whenever I curse a sacrifice?"

Kakuzu nodded. "The skeleton number."

"Skeleton number?" Hidan huffed, not trying to hide his disdain. It was almost enough to hide the atypical worry that had grown more intense on his features since days. "No reason to get disrespectful towards our God here! Skeleton number!" Taking a deep breath he continued in a calmer voice: "But yes, you see what I mean here. So, the thing about it: The moment the sacrifice is taken care of the Sense of Decay vanishes on its own again. Rather quickly I want to add. Victim gone, curse gone as well, okay?"

"I get the picture." Kakuzu had witnessed Hidan's way of killing their opponents often enough after all. Taking another sip of the tea he let his gaze wander. Now that it had become night only a weak light illuminated this room. And the way this comparatively large space was only sparsely furnished seemed to be symptomatic with how these posh places decided to show their wealth. A stark contrast to the cramped spaces of the cheaper lodging options Kakuzu deemed to be more sensible.

Hidan continued talking, failing to hide the increasing trembling in his voice. "But lately that is not what is happening! Since a while there's a spot on my arm that stays dark all the times!"

"Oh?"

"It stays dark and more: It has gotten really odd since a few days. If it is really connected to the Sense of Decay in some way, then I fear it's not a good sign at all." No longer able to hide his distress Hidan hid his face in his hand, leaving a picture of utter desperation.

Not knowing how to react Kakuzu stayed still, getting gripped by an odd tension himself. "Hidan?"

"I thought the matter would go away on its own. But it's only gotten worse. Since this week I'm really sure something is up with it."

"How so?", Kakuzu heard himself ask, not even having planned to say something. The memory of an earlier picture inserted itself into his mind, how Hidan had tried to cheer him up over the fact they had been forced to spend so much money on tonight's stay in this inn. In the meanwhile Kakuzu was certain the gesture had not only been conscious on Hidan's part but genuine as well. But he still didn't know how to react towards it.

Hidan stopped hiding his face behind his hand but kept his gaze lowered, looking unhappier than ever.

Kakuzu cleared his throat: "Want to show me what the matter is? With your arm I mean?"

Hidan sighed, looking as if he had reached a decision. He started loosening the belt of the yukata the inn had held ready in the bath. "It's on the inside of my upper arm. Maybe it's not connected to Jashin-sama after all but if it is then it can't mean something good. It just can't." With this he shoved away the collar of the yukata, freeing his arm from fabric entirely. "The spot was all blurry in the beginning but in the meanwhile it's gotten clearer", Hidan said, gesturing at the word written on his arm: "Soulless."

Kakuzu felt an electric jolt run through his body, almost twitching together in shock. He kept staring at the letters on Hidan's arm, forming themselves into this familiar word. When Hidan continued talking Kakuzu had trouble for a moment understanding his words; it felt as if someone had put wool into his ears, numbing out all sound reaching him: "Do you think it's a signal my efforts for Jashin-sama aren't enough? Everything I do for him is for the goal of making my soul worthy in a way he seems fit and now this!"

Kakuzu was still staring at the word forming itself of Hidan's arm. Trying to pull himself out of the numbness that still held him in its grip Kakuzu tried searching for words: "I don't think that's it. Those words don't have anything to do with that Jashin of yours, don't worry. The meaning of this mark isn't supposed to be taken literally either. But instead in an entirely symbolic matter." Forcing himself to look away from the mark, up into Hidan's eyes, Kakuzu continued: "It doesn't mean you do lack in fact, a soul."

A restless light flickered behind Hidan's eyes, burning away the last bit of his composure. "How can you be certain about this? You sound so certain about this! Why are you so certain about this?"

There was no longer a way Kakuzu could avoid getting into this part of the conversation, wasn't there? As if on its own volition his hand brushed the strand of hair falling into his face aside, revealing the small spot behind his ear. "Because I'm just the same."

For a moment that felt unspeakably long Hidan stayed silent, staring at the spot with widened eyes. Then he cautiously leaned towards Kakuzu, getting a better look. "You have the same word. 'Soulless'. It's not a tattoo, isn't it?"

"No, it isn't. It turned up on its own, already some time ago. In just the same manner you just described."

"But what does it mean?!", Hidan practically groaned, the exhaustion he had held at bay until now descending upon him.

It was funny. Being the impulsive person Hidan tended to be, it was easy to do the mistake to assume he possessed no self-control. The opposite was the truth though: The majority of the time Hidan kept a grip on himself, forbidding whatever restless shape was simmering in the most forlorn corner of his mind to manifest. It wasn't even a struggle that went by invisible; if you payed enough attention you could see it in his eyes. But just as most people avoided getting a better look at the bit of Kakuzu's face that wasn't hidden away by his facial mask (let alone the refusal to meet his eyes once his stitched face was fully visible), most people didn't bother to look at more than was visible on the surface of what Hidan displayed.

Kakuzu threw the long strands of his hair over his left shoulder, ensuring the word behind his ear would stay visible. Taking a deep breath he tried his best to explain: "I did some research on it. Basically it's a special form of jutsu. It shares similarities with how bloodline limits manifest, though calling it that would not be correct. It's something you're born with as well though, you can't get this kind of technique using artificial methods."

"Oh!?"

"It's not genetic though. It seems to turn up at random."

"So it's not connected to Jashin-sama!" Cautious hope flickered up on Hidan's face.

"It isn't."

"You have no idea how glad I am to hear this! Oh, fuck!" Hidan let hear an exhausted groan, the tension that had let him sit upright until now leaving, making him slouch down on the floor. Getting a bit of his composure back he looked at Kakuzu: "So, there's a bunch of people out there having this 'Soulless' mark as well, or how does this work?"

Kakuzu felt a joyless smile show up on face. Now came the tricky part. "No, every pair has another name."

"Pair?"

"It's always two people sharing the same name with each other. It's a fighting based jutsu, those two people sharing a name form a tag team. This allows them to use the abilities this jutsu offers."

Sitting upright again Hidan straightened his back, absentmindedly ordering his yukata back into place again. Beginning to look sceptical he said: "Wait, I just realized our marks don't look quite identical after all. Mine is written in lower case letters, yours in upper case ones."

Beginning to feel defensive Kakuzu folded his arms in front of his chest. His wandering gaze got stuck at the lantern illuminating the room. What a fancy crap. Couldn't they use electric lights like everyone else? The bath of the place had neon lights keeping everything bright, so it was not like this was a matter of lacking resources. "That signals our respective roles in the fighting formation."

Hidan angled his head, looking more sceptical with every passing second.

"It works like this: I give the orders, you do the fighting."

Hearing this Hidan legitimately looked offended. "There's no way I let you order me around like that!"

"Otherwise the fighting options this jutsu offers won't work though." Kakuzu tried suppressing the irritation starting to flare up in his stomach. "Look, I'm just letting you know what I managed to find out about this type of jutsu. It's not like I'm making this up!"

Rolling his eyes Hidan slouched down on the floor again. Still looking miffed he took a sip of his tea, immediately wrinkling his nose in distaste. "It's gotten cold by now, ugh."

"Since when do you mind cold tea?", Kakuzu asked, taking a sip of his own cup. Not because he was feeling particularly thirsty, he just couldn't stand to sit still doing nothing any longer.

"Well, today I mind it! I usually don't mind but today I do!"

Kakuzu huffed, directing a small smile at Hidan. "With the prices this place charges you can demand for it to stay hot longer."

"See? And it's cold as fuck tonight, the warmth of this tea is needed with good reason", Hidan said, starting to sound more content again. Despite his complains he emptied his cup anyway. Making a more collected impression again he gave Kakuzu a questioning gaze. "So, fighting together like this will offer us new battle options, or what?"

"Yes, basically. We will have to try out what works for us though; there are differences what fighting style fits best, varying from pair to pair."

The grin Hidan was giving Kakuzu now looked downright daring. "Can't wait to find out with what ideas you're going to try ordering me around."

"If it is any comfort for you, it won't be you who will get the damages if you mess up. Any injury you obtain while we're fighting under that jutsu will be directed at me. So it's not like this whole situation is ideal for me either."

Hidan's face went blank hearing this. "You mean I don't get injured when receiving a blow, but you do?"

"That's what the texts said. Your ability to fight increases like this, but it's me suffering the effects of any damage."

"This sounds somewhat like how I prepare sacrifices when fighting. Are you sure this jutsu isn't connected to Jashin-same in any way?"

"Quite" Kakuzu sighed. "This jutsu is based on our connection, not to any religious practice. I don't know what else to tell you."

"This is all so complicated!", Hidan groaned, flopping down on the floor. "I thought I had no blood line limit working for me and now this!"

"It's not a bloodline limit, I just told you." Holding up his hand Kakuzu decided to give in to an urge that had flared up from time to time in all the years he had been aware about his true name. "Don't get startled, I want to try something out."

Hidan leaned up on his elbow, looking alarmed: "Wait! Don't mess around like this; you sure you know what you're doing here?"

Ignoring Hidan's objections Kakuzu gave in to the pull that had affected his mind for twenty years. The next moment a thin silvery thread appeared, connecting his wrist to Hidan's "It works!"

"What's this?!"

"A line connecting us", Kakuzu said, stating the obvious. "Like this we will always find each other, even if we lose another."

Hidan's eyes stayed put on the line connecting them, then looking at the spot the thread was wrapped around his own wrist, then at the other end that wrapped around Kakuzu's. "Well, I guess… I guess this has potential to be practical." Despite his words Hidan had not sounded pleased.

Kakuzu shrugged his shoulders, making the silvery thread disappear again. "Exactly. So make sure you'll know how to do this as soon as possible as well."

Hearing this Hidan went still, giving Kakuzu a defiant stare. "I might consider listening to your suggestions once we try that battle style you just mentioned, but ordering me around outside of this won't fly, understood?"

"Consider listening to my suggestions more often. If you had done so yesterday's target wouldn't have managed to cut off your leg", Kakuzu said, holding Hidan's gaze.

"That's… who asked you?" Shaking his head in disbelieve Hidan continued to eat, set on letting the remaining bit of food still on his plate vanish. "At least the word has nothing to do with Jashin-sama", he muttered under his breath, refusing to look at Kakuzu, gaze strictly set on his plate.

Kakuzu brushed his hand through his hair, letting it cover the spot behind his ear again. "Hasn't that gotten cold in the meanwhile as well?

Hidan shortly glanced up at him. "It has but I don't really care." He paused, looking towards the window that at this point showed nothing but the darkness of the night, only occasionally possessing enough brightness to show glimpses of the snowstorm that was turning the world around them into an unseen white. "Guess I'm still a bit in mountain monkey mode after all", he said, a smile showing up on his face that looked halfway embarrassed and halfway relieved.

Once he was done with eating Hidan wordlessly picked up his rosary, giving the pendant a thoughtful look. He still had his eyes fixed on it when he started talking: "So, it's not a bloodline limit. And every tag team has their own name. But how do these pairs get picked then?"

Kakuzu lowered his gaze, letting his hair fall into his face, trying to hide the blush starting to appear on his face. "According to that book it's a question of compatibility. That jutsu connects people whose personalities fit together best."

Hidan leaned forward, unable to hide his excitement. "You mean like soulmates?!"

"No, not like… who was talking about soulmates? You have the potential for displaying this jutsu and once there's someone near you being a good fit the both of you become a wielder. That's how the research on the matter explained it." Kakuzu would know. Since his first trip to that library in that forgotten town twenty years ago he occasionally had looked up the matter again. In case there would have been any new research developments in the meanwhile.

"That's totally soulmates!", Hidan insisted, the excitement in his voice not wavering in the slightest. It came as little surprise to Kakuzu that the next moment Hidan had thrown his arms around Kakuzu's shoulders, hugging him close.

"Still in mountain monkey mode, I see", Kakuzu grumbled, not bothering to keep the resignation out of his voice.

Hidan just tightened his grip around him, displaying unhidden glee. "You usually never complain about that."

"Oh, is it that what it is called now?" If Hidan was trying to put embarrassing euphemisms to that part of their relationship, Kakuzu would play no part in it.

"Still feeling grumpy?"

"I'm not grumpy."

"Fine, you're not then." Hidan hadn't sounded convinced. He went still for a moment, thinking. "Wait. Is that why you always keep on your mask when we're having sex? To hide away the mark behind your ear?"

"What I… I don't always keep the mask on when we're sleeping with each other!"

"You totally do!"

Feeling his resolve crumble Kakuzu no longer bothered suppressing a sigh. "If I do it's not intentional." Not fully. Trying to distract from the matter he leaned further into Hidan's embrace.

Outside the snowstorm was still going, its dull roaring echoing through the room, now that the two of them had become silent.

Hidan turned his head, looking at Kakuzu, the light behind his eyes displaying a tense caution that started seeping into his voice. "Kakuzu? I'm just saying if I have to have a soulmate, then I'm glad it's you."

Well. Now that Hidan had put it so clearly into words Kakuzu realized that his sentiments about the matter were the same. He also realized there was no way he could admit this directly either. Forcing his body into motion he put his arms around Hidan, pulling him closer. "Make sure you get a hang on how to let that silvery thread appear. In case we ever get separated during battle or the like, it might turn out to be useful."

Hearing this Hidan's smile deepened, chasing away the last bit of doubt having lingered on his face. "Sure thing old man! Looks like you're not getting rid of me that easily again, I'm sorry to inform you."

Kakuzu felt himself smile back. "I'm sure I'll somehow manage."

_**The End**_


End file.
